公开(公告)号：US20240267129A1

公开(公告)日：2024-08-08

申请号：US18565433

申请日：2021-06-08

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Masanori NAKAMURA ,  Takayuki KOBAYASHI ,  Yoshiaki KISAKA ,  Yutaka MIYAMOTO

IPC: H04B10/61

CPC classification number: H04B10/6161 ,  H04B10/613

Abstract: A receiver convolves an impulse response for compensating for frequency characteristics and a complex impulse response for wavelength dispersion compensation with each of a real component and an imaginary component of each polarized wave of a reception signal. For each polarized wave, the receiver performs complex signal processing of multiplying the imaginary component by the imaginary unit, then branching the resulting component, and adding one imaginary component to the real component. For each polarized wave, the receiver uses, as input signals, the real component and the imaginary component of each polarized wave after complex signal processing and the phase conjugates of them. For each polarized wave, the receiver adds a signal obtained by a process in which each of the real component and the imaginary component of each polarized wave is multiplied by a complex impulse response, the resulting components are added, and a phase rotation is applied and a signal obtained by a process in which each of the phase conjugate of the real component and the phase conjugate of the imaginary component of each polarized wave is multiplied by a complex impulse response, the resulting components are added, and an opposite phase rotation is applied, and adds a transmission data bias correction signal.

公开(公告)号：US20220224415A1

公开(公告)日：2022-07-14

申请号：US17614686

申请日：2019-06-06

Applicant: Nippon Telegraph and Telephone Corporation

Inventor： Masanori NAKAMURA ,  Seiji Okamoto ,  Kengo HORIKOSHI ,  Shuto YAMAMOTO ,  Takayuki KOBAYASHI ,  Yoshiaki KISAKA ,  Masahito TOMIZAWA

IPC: H04B10/2513 ,  H04B10/61 ,  H03H17/02

Abstract: An electric digital received signal obtained from a received optical signal is segmented into blocks of a certain length with an overlap of a length determined in advance with an adjacent block. Fourier transformation is performed for each of the blocks. The blocks subjected to the Fourier transformation are stored consecutively in time series, a coefficient determined based on a wavelength dispersion compensation amount according to one of frequency positions and a delay amount according to one of the frequency positions and one of time positions is applied to each of frequency component values included in a plurality of the stored blocks, and the blocks to which the coefficient has been applied and which are obtained by adding up the frequency component values to which the coefficient has been applied for each of the frequency positions are generated. Inverse Fourier transformation is performed on the generated blocks to which the coefficient has been applied. A part of the overlap subjected to the inverse Fourier transformation is removed.

公开(公告)号：US20220149974A1

公开(公告)日：2022-05-12

申请号：US17433149

申请日：2020-01-31

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Takayuki KOBAYASHI ,  Masanori NAKAMURA ,  Fukutaro HAMAOKA ,  Yutaka MIYAMOTO

IPC: H04J14/06 ,  H04B10/2507 ,  H04B10/61 ,  H04L27/01 ,  H04L27/38

Abstract: A receiver convolutes each of a real component and an imaginary component of each polarization of a polarization-multiplexed reception signal with an impulse response for compensating for frequency characteristics of the receiver and a complex impulse response for wavelength dispersion compensation, and generates, as input signals, the convoluted real component and imaginary component of each polarization and phase conjugations thereof, for each polarization. The receiver generates, for each polarization, a first addition signal obtained by multiplying each of the real component and the imaginary component of each polarization by a complex impulse response, thereafter adding together the multiplied real component and imaginary component, and applying a phase rotation for frequency offset compensation to the added components, and a second addition signal obtained by multiplying each of the phase conjugation of the real component of and the phase conjugation of the imaginary component of each polarization by a complex impulse response, thereafter adding together the multiplied phase conjugations, and applying a phase rotation opposite to the phase rotation for frequency offset compensation to the added phase conjugations, and adds or subtracts a transmission data bias correction signal to or from a signal obtained by adding together the generated first addition signal and second addition signal.

公开(公告)号：US20190007955A1

公开(公告)日：2019-01-03

申请号：US16075205

申请日：2017-01-23

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Hiroshi OU ,  Takayuki KOBAYASHI ,  Daisuke HISANO ,  Tatsuya SHIMADA

IPC: H04W72/12 ,  H04W72/04 ,  H04W56/00

Abstract: A terminal station device is a terminal station device of a communication system in which a high-order device, the terminal station device, an end-terminal device, and a low-order device are communicably connected in this order, the high-order device notifies the low-order device of resource information indicating a resource that is usable in communication, and thereby the resource is allocated to the low-order device. The terminal station device includes: a band allocation unit that allocates a band that is permitted to be used by the end-terminal device for transmission processing to the terminal station device, based on an interval at which the terminal station device has received the resource information.

公开(公告)号：US20180063831A1

公开(公告)日：2018-03-01

申请号：US15558395

申请日：2016-03-25

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Hiroshi OU ,  Tatsuya SHIMADA ,  Takayuki KOBAYASHI ,  Jun TERADA

IPC: H04W72/04 ,  H04W28/20 ,  H04W72/12

CPC classification number: H04J14/0227 ,  H04J14/0228 ,  H04J14/0252 ,  H04L12/44 ,  H04L47/724 ,  H04L47/824 ,  H04W28/20 ,  H04W72/0413 ,  H04W72/12 ,  H04W88/02

Abstract: Information on allocation of a bandwidth of uplink communication of each user device is extracted from information notified by an upper-level device on the uplink communication of the user devices. Identification information of a lower-level device connected to a terminal device and identification information of the user devices are stored in correlation with each other. A bandwidth demanded for uplink communication of the terminal device is determined on the basis of the information on the allocation of the bandwidth of the uplink communication of each of the user devices and the identification information of the user devices. A start time point of the uplink communication of the terminal device and the amount of information of signals for which transmission of the uplink communication of the terminal device is allowed are allocated to the terminal device on the basis of the bandwidth demanded for the uplink communication of the terminal device.

公开(公告)号：US20250096919A1

公开(公告)日：2025-03-20

申请号：US18727823

申请日：2022-09-28

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Akira KAWAI ,  Masanori NAKAMURA ,  Takayuki KOBAYASHI ,  Yutaka MIYAMOTO

IPC: H04J14/02 ,  H04J14/06

Abstract: A characteristic measurement device that measures a characteristic between lanes of a transmitter and a receiver connected via an optical fiber transmission path, the characteristic measurement device including an adaptive equalization unit that uses a polarization multiplexed reception signal and a phase conjugate signal of the polarization multiplexed reception signal or a plurality of signals mathematically equivalent to the reception signal and the phase conjugate signal of the reception signal as input signals and performs equalization processing on the input signals, and a characteristic function derivation unit that calculates a first inverse characteristic representing an inverse characteristic of the transmitter and a second inverse characteristic representing an inverse characteristic of the receiver on the basis of a filter coefficient obtained at the time of the equalization processing performed by the adaptive equalization unit and a frequency offset.

公开(公告)号：US20250047382A1

公开(公告)日：2025-02-06

申请号：US18708981

申请日：2021-11-17

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Shimpei SHIMIZU ,  Takayuki KOBAYASHI ,  Yutaka MIYAMOTO

IPC: H04B10/2507 ,  H04B10/291

Abstract: An optical transmission system, comprising:
a transmission unit that maximizes a frequency interval between a plurality of channel components within a transmission band, and generates a first optical signal that is an optical signal in which the plurality of channel components are wavelength-division multiplexed, a first transmission path for transmitting the first optical signal, a phase conjugate conversion unit that generates a second optical signal by inverting a spectrum of the first optical signal, and a second transmission path for transmitting the second optical signal. The first transmission path and the second transmission path wavelength-disperse the plurality of channel components of the first optical signal and the second optical signal. The first transmission path may include one or more first optical relay units for amplifying and relaying the first optical signal. The second transmission path may include one or more second optical relay units for amplifying and relaying the second optical signal.

公开(公告)号：US20240413922A1

公开(公告)日：2024-12-12

申请号：US18695580

申请日：2021-09-29

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Akira KAWAI ,  Takayuki KOBAYASHI ,  Masanori NAKAMURA ,  Shimpei SHIMIZU ,  Yutaka MIYAMOTO

IPC: H04J14/04 ,  H04B10/2581 ,  H04B10/516

Abstract: One aspect of the present invention is an optical transmission system including a transmitter connected to a transmission line having M spatial channels, and a receiver that receives a signal transmitted from the transmitter via the transmission line, wherein the transmitter includes: an allocator that allocates a transmission bit string transmitted to the transmission line into a bit string serving as a basic signal and a bit string serving as spatial channel information; a generator that generates N (M>N) signals from the bit string serving as the basic signal allocated by the allocator; and a selector that selects N spatial channels, through which the N signals generated by the generator are transmitted, from the M spatial channels on the basis of the bit string serving as the spatial channel information allocated by the allocator.

公开(公告)号：US20240259095A1

公开(公告)日：2024-08-01

申请号：US18290350

申请日：2021-05-18

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Akira KAWAI ,  Takayuki KOBAYASHI ,  Masanori NAKAMURA ,  Shimpei SHIMIZU ,  Yutaka MIYAMOTO

IPC: H04B10/079

CPC classification number: H04B10/0795

Abstract: A waveguide estimation device includes: a time window processing unit that multiplies time-series tap coefficients of an adaptive filter by a time window function; and an estimation unit that estimates at least one of a differential group delay in a frequency series or a time series and a polarization dependent loss in a frequency series or a time series based on the time-series tap coefficients in a time window. The estimation unit may estimate at least one of the differential group delay in a frequency series or a time series and the polarization dependent loss in a frequency series or a time series based on a tap coefficient exceeding a lower limit threshold value or falling below an upper limit threshold value among the time-series tap coefficients in a time window. The estimation unit may estimate the average value of the differential group delays in a frequency series or a time series. The time window processing unit may determine the length of the time window based on a constant multiple of the average value.

公开(公告)号：US20230059003A1

公开(公告)日：2023-02-23

申请号：US17797266

申请日：2020-02-12

Applicant: NIPPON TELEGRAPH AND TELEPHONE CORPORATION

Inventor： Shimpei SHIMIZU ,  Takushi KAZAMA ,  Takayuki KOBAYASHI ,  Yutaka MIYAMOTO

IPC: H04B10/2525

Abstract: A wavelength dispersion compensating apparatus, including: a signal light generating unit which generates, from predetermined signal light, signal light having a phase correlation centered on a degenerate frequency of a phase sensitive amplifier; a dispersion compensation transmission path which compensates for a wavelength dispersion of the predetermined signal light included in the signal light; a filter which compensates for a residual wavelength dispersion after compensation by the dispersion compensation transmission path of the predetermined signal light included in the signal light; a phase sensitive amplifier which amplifies the signal light input via the dispersion compensation transmission path and the filter; a residual wavelength dispersion calculating unit which calculates a residual wavelength dispersion amount based on a measurement result of output light amplified by the phase sensitive amplifier; and a filter control unit which controls the filter so as to add a wavelength dispersion that cancels out the calculated residual wavelength dispersion amount to the predetermined signal light.